Rigid airship



Jan. 22; 1929.` 1,700,095

P. HELMA RIGID AIVRSHIP Filed Dec. 4, 1925 Patented Jan. 22, 19?..9.`

UNITED STATES PATENT OFFICE.

PAUL HELMA, OF AKRON, OHIO, ASSIGNOR TO GOODYEAR-ZEPPELIN CORPORATION, OF AKRON, OHIO, A CORPORATION OF DELAWARE.

RIGID .AIRSHIR Application filed December 4, 1925. Serial No. 73,214.

My invention relates to rigid airships and it has particular relation to the structure and shape of the transverse rings and cross frames constituting a part of the hull structure of rigid airships.

One object of my invent-ion is to provide a rigid airship whose fabricated struct-ure is so formed that the load forces acting thereon will cause tension stresses only in a major portion of the hull structure.

Another object of my invention is to provide a hull structure for rigid airships which includes spaced load carrying gangway structures, the portion of the hull structure above the gangway structures being so formed that the cross-sectional contour thereof corresponds to the curve of the resultants of the buoyant gas forces acting on the hull of the airship.

In building airships having transverse main and auxiliary rings or frame members included in their structure, it is known that certain advantageous results may be obtained by arranging the loads at opposite sides of the vhull structure, below the horizontal diameter thereof instead of suspending the loads directly along the keel or central line of the lower portion of suc-h structure. The transversely arranged rings are adapted to withstand stresses more efficiently when the loads are disposed at the sides of the airship.

I-Ieretofore, in airships of the type designed in such manner that their cross-sectional contour was substantially circular or of the contour of an equilateral polygon, the buoyant gas forces acting upon the intermediate transversely arranged rings were transmitted through the side panels of the hull to the transversely arranged main rings, and the counteracting loads also were transmitted to the main rings through the longitudinally disposed gangway structure which was disposed along the lower central line of the airship. This type of structure created the disadvantage of compelling the forces and counter forces acting at a given crosssection of the airship to be transmitted by way of bending stresses to relatively remote points in order to obtain statical equilibrium.

An airship designed according to my invention will obviate the disadvantagesabove ment-ioned by providing novel structures of main and auxiliary rings which will balance the forces acting thereon. Two spaced gang- Y rings.

way structures are provided at opposite sides of the lower center line of the airship and are spaced from the respective medial side portions of the airship hull. Those portions of t-he transverse main and auxiliary or intermediate rings above the side gangways are so constructed that they assume a shape in cross-section which corresponds to the curve of the resultants' of the gas forces acting upon the hull of the airship from the interior. lThus in the normal inflated condition of the gas bags no forces whatever will be transmitted through the side panels of the airship and no bending forces will occur in the auxiliary or intermediate rings.

From this discussion it will be apparent that the intermediate transversely arranged rings under conditions of load are subjected to purely tensional stresses which are transmitted directly to the load sustaining ygangway structures and accordingly the gangway loads are supported directly by the buoyant gas forces within the gas bags acting on the intermediate rings as well as on the main Therefore, under normal conditions of inflation of the gas bags the transverse main rings and the auxiliary rings function in the same manner. Consequently both types of rings are constructed to assume the same shape. Under all abnormal conditions such as occur during construction of the airship or during deflation of al gas bag, the main rings function to maintain the form of t-he airship and to balance the forces acting thereon. f d

The portion of the airship below the gangway structures may be designed to conform in cross-section to any desired shape but with a view to maintaining as-much as possible, whatever aero-dynamical buoyancy that may be lost because of the fact that the tension line shape of the airship must be somewhat *oblong in cross-sectional contour. It is to be understood that my invention is adapted to be applied to airships whose transverse main rings are reinforced by means of diametrically disposed wire or other braces, as well as to airships whose main rings are not provided with such braces.

For a better understanding of my invention, reference may now be had to the accompanying drawing forming a part of this specilication, and which illustrates one form which my invention may assume, although it is to be understood that this drawing is diatherefore my invention is the specific form shown grammatical, and not restricted to therein.

In one practical embodiment of'my invention, I have illustrated an airship hull 10 comprising` a plurality of transversely extending main rings 11 and 12 provided respectively with transversely disposed struc-I tural elements 13 and 14, and a plurality of transversely arranged auxiliary or intermediate rings 15 spaced at regular intervals from the main rings. lf desired diametrically disposed tension wires or other suitable members 16 may be employed to reinforce the main rings. The hull structure also 1ncludes longitudinally arranged reinforcing girders 17. A gas bag 18 of conventional type is lispose'd Within the hull 10.

rlfhe hull structure 10, including the main and auxiliary rings, comprises an upper section 19 and a lower section 20, which. sections are integrally connected by means of spaced gangivay structures 22 and 13, which extend as far as desired along the length of the airship. rlhese gangway structures are adapted to sustain the load imposed by the buoyant gas forces acting Within the gas bags against the upper section 19 of the hull structure. On the other hand there are no appreciable buoyant gas forces acting on the lower section 20 of the hull. l

In order to provide an eilicient hull structure which may be constructed of relatively light material, the upper section 19 so formed that the cross-sectional contour thereof corresponds to the curve of the resultants of the gas forces acting within the gas bag 18, and these forces under conditions of load 'impose tensional stresses only upon the upper hull structure 19, which forces are transmitted directly to the gangyvay structure 22 and 23. The cross-sectional contour of the upper section 19 may also be described as corresponding substantially to the cross-sectional contour Which a free inflated gas bag will assume.

'.ihe lower section Q0 of the hull, which is disposed between the gangwvay structures 22 and Q3 may designed to assume any convenient shape 'with a view to maintaining a regular contour of the lower portion of the ansliip. In this airship structure a line drawn mid-way between the upper and lower extremities of each main and auxiliary ring defines the maximum cross-sectional lwidth thereof.

From the foregoing description, it will be apparent that an ail-ship designed according to my invention provides a relatively uniform load supporting struct-ure, and, due to the fact that the gas bags under conditions of normal inflation will impose tensional stresses only upon the upper portion of the hull, a material saving may be effected in the Weight and amount of material employed in the fabricated structure, Without sacrificing strength or efficiency in operation of the airship.

Although I have illustrated but one form which my invention `may assume7 and have described in detail but a single application thereof, it Will be apparent to those skilled in the art that it is not so limited but that various minor modifications and changes may be made therein Without departing from the spirit of my invention or from the scope of the appended claims.

What l claim is:

1. An airship comprising a gas bag and a jointed hull structure having a major portion of its cross-sectional contour conforming to the shape of the catenary resulting from the forces composed of the dead Weight of the hull and of the buoyant forces at normal inflationof the gas bag, said composed forces being transmitted to the oints of the airship hull.

2. An airship comprising a gas bag and a jointed hull structure provided with longitudinally extending spaced gangway structures disposed at opposite sides of the lovver center line of the hull, the major portion of the cross-sectional contour of the hull conforming to the shape of the catenary resulting from the forces composed of the dead Weight of the hull and of the buoyant forces at normal inflation of the gas bag, said composed forces being transmitted to the joints of the airship hull.

3. An airship comprising gas bags, a jointed hull having its maximum Width in a horizontal plane equi-distant from the top and bottom thereof and longitudinally extending spaced ganguf'ays disposed at opposite sides of the lower center line of the hull, the major portion of the cross-sectional contour of the hull conforming to the catenary resulting from the forces composed of the dead Weight of the hull and of the buoyant forces at normal inflation of the gas bag, said composed forces being transmitted to the joints of the airship hull. y

1l. An airship comprising a hull structure including transversely extending main rings adapte d to enclose a gas ba and longitiidiiially disposed gangway structures intersecting the main rings at opposite sides of the lower central portions thereof, the main rings being so formed that under normal conditions of intl-ation, the forces exerted by the buoyant forces ofthe gas bag impart tensional stresses only to the main rings.

5. An airship comprising a. hull structure including transversely arranged auxiliary rings, a gas bag Within the hull, longitudinally disposed gangway structures intersecting the auxiliary rings atopposite sides of the loyver central portions thereof, the auxiliary rings being so formed that under normal conditions of inflation the buoyant forces exerted by the gas bag impart tensional stresses only to the auxiliary rings.

6. An airship comprising main rings and auxiliary rings, gangway structures in the lower portion thereof intersecting the said rings and gas bags disposed Within the rings, the rings being so designed that load forces caused by the buoyancy of the gas bags create tensional stresses only in the main rings above the gangway structures.

An airship comprising a rigid fabricated hull structure having a normally inflated gas eell therein exerting buoyant forces against the interior of the hull to support the Weight of the latter, the cross-sectional contour of the hull corresponding substantially to the Curve of the resultants of the buoyant gas forces transmitted through the gas cell in its free inflated condition While sustaining a Weight equal substantially to that of said hull.

In Witness whereof, I have hereunto signed 

